Sky Liners

We know we can float a really heavy cabin and engines with nothing but a sack of helium or hydrogen gas, but sadly, we also know that doing so is very impractical when you want to go somewhere. But it seems to me that, floating around on a cruise liner for months just to get across the ocean is still pretty inefficient, and yet people still do it just for the heck of it. What if airship travel could be made simple and efficient again? How much would people pay to be aboard a floating piece of heaven?
Instead of a cigar shaped blimp, we make a balloon with dynamic shape so that it can both round out into your standard "cigar" shape or flat out into a massive sail, which would "sail" itself. Attached to the contraption would be a medium barge sized passenger cabin that can be made totally out of a fiberglass outer hull and a not so opaque inner hull which can be pulled back to give riders a magnificent view. Such a device will sail in the jet streams, probably going faster that it would on engines, and its own motors will only be used during takeoffs and landings.